Surgical knife with replaceable blade



Feb. 6, 1968 A. w. WARD ETAL. 3,357,335

SURGICAIJ KNIFE WITH REPLACEABLE BLADE Filed Oct. 22, 1965 INVENTOR ABRAHAM w WARD RHJ MONDT. WH/PPLE FIGZ United States Patent 3,367,335 SURGICAL KNIFE WITH REPLACEABLE BLADE Abraham W. Ward, 1125 Greenwich St., San Francisco, Calif. 94109, and Raymond T. Whipple, 673 Bille Road, Paradise, Caiif. 95969 Filed Oct. 22, 1965, Ser. No. 501,370 3 Claims. (Cl. 128305) ABSTRACT OF THE DISCLOSURE A surgical knife is disclosed as including a stem having a longitudinal slot in the outer end thereof, and a cross pin extending across the slot near the inner end of the slot. A sleeve is telescoped on the stem and is spring biased outwardly to enclose the open sides of the slot. A knife blade is provided with 'a base portion which fits within the slot and has a laterally extending notch engageable with the cross pin, the base portion continuing at an angle as a shank portion with a blade portion at the outer end of the blade extending at substantially right angles to the shank portion. By retracting the sleeve against the bias of the spring, blades can be interchangeably engaged with the cross pin in the slot, and be held in position by allowing the sleeve to be biased to its outer position.

This invention relates to surgical knives and especially to knives designed for operation on the gums for the treatment of pyorrhea or similar conditions. The knife blade is preferably arranged in an angular position with respect to the handle enabling it to be most effectively used for operations upon the gums. The blade in its preferred form is also provided with a single bevelled cutting edge, the inside surface of the blade being a plane surface and the outer side of the blade being smoothly bevelled so that the cutting edge is coincident with the inner plane surface. This enables the blade to be very easily sharpened by simply applying the plane surface to the stone.

In the accompanying drawings an embodiment of the invention is illustrated, the invention, of course, being capable of application in many different forms.

A preferred form of the invention is shown in FIGS. 1 to 6 inclusive. In these figures,

FIG. 1 is a perspective view of a blade;

FIG. 2 is a side elevation of a knife embodying the form of blade shown in FIG. 1;

FIG. 3 is an enlarged vertical sectional view of the upper part of the knife and blade shown in FIGS. 1 and 2;

FIG. 4 is a vertical section of the parts shown in FIG. 3 taken in a plane at right angles to the plane of FIG. 3;

FIG. 5 is a transverse section on line 5-5 of FIG. 3; and

FIG. 6 is a view similar to FIG. 4, but with the blade in the position to be inserted into or removed from the handle.

Referring to the drawings in detail, the blade is preferably formed of sheet steel and is mounted so that the edged portion occupies an angle of approximately 45 to the axis of the handle. The handle 10 has a neck 12 having at its upper end a stem 14 of reduced diameter on which is fitted a coil spring 16 which rests on a shoulder 18. The upper end of the stem 14 is split by a slot 20 and carries a cross pin 22. The blade proper 24 has a shank portion 26, the portions 24 and 26 being approximately at right angles to each other. The part 26 terminates in a base portion 28 which fits in the slot 20 in the upper end of the stem 14 and has a transverse notch 32 therein which engages the pin 22. Notch 32 is open at one side so that it may engage the pin and is preferably inclined slightly from the horizontal position so that it slopes up a little. Mounted on the neck 12 is a sleeve 34 which is recessed as indicated at 36 to enclose the spring 16. When mounting the blade, the sleeve 34 is pushed down as shown in FIG. 6 and the notch 32 is slipped over the pin 22. The blade is then straightened with respect to the stem and the spring pushes up the sleeve 32 which then holds the blade firmly in the position as shown in FIGS. 2, 3 and 4. A simple, but firm connection, is thus made between the blade and the stem 14. As will be obvious, the blade can be removed by simply pressing down the sleeve 34 'and unhooking the blade from the pin 22.

The blade 24 may be made of any appropriate shape for the work intended to be performed. As illustrated, it is a double edged blade beveled along the outside so as to form an edge lying in the plane of the inside of the blade. The blade has a shoulder 38 so as to limit outward movement of the sleeve 34.

It will be understood that the embodiment of the invention illustrated shows only one example of the invention but that many changes may be made without departing from the spirit and scope thereof.

What is claimed is:

1. A knife for oral and general surgery comprising a handle having a stem at one end thereof, a coil spring mounted on the said stem, said stern having a longitudinal slot in the end thereof and having a cross pin extending across the slot, a blade having a base portion received in said slot and having a transverse notch therein engageable with said cross pin, a shank portion at the end of said base portion making an angle with the axis of the handle, said shank portion having a blade portion at the outer end thereof at approximately right angles to the plane of said shank portion, and 'a sleeve slidably mounted on the stem portion and enclosing said coil spring and movable from a position in which the spring is compressed so as to permit the notch in the base portion to be disengaged from said cross pin to a position enclosing said base portion and holding the blade portion in operative position for cutting.

2. A knife for oral and general surgery, comprising a handle having a stem at one end thereof, said stem having 'a longitudinal slot in the end thereof and having a cross pin extending across said slot, a blade having a base portion received in said slot and having a transverse notch therein engageable with said cross pin, said blade including a shank portion extending from said base portion and having a blade portion at the outer end thereof, and a sleeve slidably mounted on said stem and movable along said stern between a retracted position, in which said slot is exposed to an extent sufiicient for engagement of said notch in said base portion with said cross pin, and an extended position in which said sleeve laterally encloses said notch and said base portion of said blade and holds the blade portion in operative position for cutting.

3. A knife for oral and general surgery, as claimed in claim 2, in which said shank portion extends at an angle to the axis of said handle, and said blade portion extends at approximately right angles to the plane of said shank portion.

References Cited UNITED STATES PATENTS 3/1914 Swasey 128-305 7/1954 Fahlgren 30-329 X 

